Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Mon Jul 22 2024 Valid 12Z Mon Jul 22 2024 - 12Z Wed Jul 24 2024 ...Major to locally extreme Heat Risk expected to expand from the Great Basin into the northern High Plains by Wednesday as well as over portions of the Central Valley of California... ....Scattered thunderstorms across the southern Plains to the Southeast today near a stalled front will gradually shift toward the East Coast as another front will spread additional thunderstorms across the Great Lakes to New England Tuesday and Wednesday... ...Monsoonal thunderstorms continue across the Great Basin and into the Four Corners region with threat of localized flash flooding... A slow-to-evolve summertime weather pattern continues across the U.S. mainland as we head into late July. This weather pattern will sustain the ongoing heat wave across the western U.S. while maintaining cooler than normal temperatures across the mid-section of the country and into portions of the East Coast. The prolonged nature of the heat in the West will keep the Heat Risk at major to locally extreme levels across portions of the Central Valley of California, and the Great Basin today where another afternoon of triple digit high temperatures is expected. Meanwhile, a Pacific cold front will set things in motion a bit as the front moves inland across the Pacific Northwest through the next couple of days. Triple-digit high temperatures will then expand eastward into northern High Plains by Wednesday ahead of the front while 110s will persist across the Desert Southwest and 100s in the Central Valley of California. Please continue to practice heat safety in this persistent and prolonged heat wave in the western U.S. In contrast, cooler than normal temperatures will prevail across the mid-section of the country and into portions of the eastern U.S. where a stalled front will keep plenty of clouds along with scattered thunderstorms. These thunderstorms are not expected to be potent but they could result in localized flooding issues from time to time across the southern tier states. The upper-level pattern and instability that support these thunderstorms from the southern Plains to the Southeast today will gradually expand northeastward into the eastern U.S. on Tuesday and then generally affect areas from across the Deep South into much of the East Coast by Wednesday. Another cold front from eastern Canada will dip into the northern tier states, bringing additional thunderstorms across the Great Lakes to New England Tuesday and Wednesday. Meanwhile, monsoonal thunderstorms will continue across the Great Basin and the Four Corners region with the threat of localized flash flooding for the next couple of days. Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php